Halley's Comet is the most famous comet that can be observed from Earth. There are many stories and superstitions associated with it. In different eras, people perceived her periodic appearances differently. It was considered both a divine sign and a devilish curse. A bright star with a glowing tail inspired fear and promised change.
Discovery of a comet
The comet was observed in antiquity. A mention of it has come down to us, dated 240 BC. For a long time it was believed that comets are perturbations and whirlwinds in the earth's atmosphere. Tito Brahe, a Danish astronomer, determined by measurements in 1577 that the orbit of Halley's Comet lies outside the Moon, in space. But it was not clear whether the comet was flying along a rectilinear trajectory or moving in a closed orbit.
Halley's Research
The answer to this question was given by the English astronomer Edmund Halley in 1687. He noticed that the comet was either approaching the Sun or moving away from it, which did not correspond to rectilinear motion. Compiling a catalog of the orbits of comets, he drew attention to the records of observations of livingscientists before him and made the assumption that the comets 1531, 1607, 1687 are one and the same celestial body. Having carried out calculations in accordance with Newton's laws, Halley predicted the appearance of a comet in 1758. This prediction came true after his death, although with a delay of 619 days. The fact is that the period of revolution of Halley's comet depends on the gravitational interaction of the giant planets Jupiter and Saturn and, according to modern studies, can be from 74 to 79 years. The comet whose periodicity was discovered by Halley was named after him.
Comet properties
Halley's comet belongs to the class of short-period comets. These are comets with a rotation period of less than 200 years. It revolves around the Sun in an elongated elliptical orbit, the plane of which is inclined to the plane of the ecliptic by 162.5o, and it moves in a direction that is opposite to the movement of the planets. The speed of the comet relative to the Earth is the largest among all the bodies of the solar system - it is 70.5 km / s. Mathematical modeling shows that the comet has been in orbit for approximately 200,000 years. But these data are approximate, since the influence of the Sun and other planets is very diverse and unpredictable deviations are possible. Its expected lifetime in orbit is 10 million years.
Halley's comet belongs to the family of Jupiter's comets. Currently, the catalog of such celestial bodies includes 400 comets.
Composition of the comet
When the comet last appeared in 1986, it wasthe research probes "Vega-1", "Vega-2" and "Giotto" were launched. Thanks to their research, it was possible to find out the composition of the comet. These are mainly water, carbon monoxide, methane, nitrogen and other frozen gases. Evaporation of particles leads to the formation of a comet's tail, which reflects sunlight and becomes visible. The configuration of the tail can change under the influence of the solar wind.
Comet density 600 kg/m3. The core consists of a pile of debris. The core consists of non-volatile materials.
Research on Halley's comet continues today.
Comet appearances
In the 20th century, Halley's Comet appeared in 1910 and 1986. In 1910, the appearance of a comet caused panic. Cyanide, a poisonous gas, was found in the spectrum of the comet. The properties of potassium cyanide, the strongest poison, were already well known. He was popular with suicides. All of Europe waited in horror for the arrival of a poisonous heavenly guest, apocalyptic forecasts were published in the newspapers, poets dedicated poems to her. Journalists competed in wit, and a wave of suicides swept across Europe. Even Alexander Blok wrote in a letter to his mother about the comet:
Its tail, consisting of cinerod (hence the blue gaze), can poison our atmosphere, and all of us, reconciled before death, will sweetly fall asleep from the bitter smell of almonds on a quiet night, looking at a beautiful comet…
Enterprising charlatans put on sale "anti-comet pills" and "anti-comet umbrellas", which were instantly sold out. There were suggestions in the papersrental of submarines for the duration of the comet's flyby. The comic ad said that you would spend several days under water, and then the whole Earth would belong to you completely. People discussed the possibility of escaping by hiding in a barrel of water.
Comet writers
Mark Twain wrote in 1909 that he was born in the year of the comet's appearance (1835), and that if he did not die on her next visit, this would greatly disappoint him. This prediction came true. He died in 1910 when the comet was at perihelion. Voloshin and Blok wrote about the comet.
Igor Severyanin said that "Premonition is more painful than a comet".
Cataclysms and a comet
With the advent of Halley's comet, mankind associated disasters occurring on Earth. In 1759, there was a huge eruption of Vesuvius, the king of Spain died, a wave of hurricanes and storms swept the world. In 1835, a plague broke out in Egypt, a powerful tsunami took place in Japan, and there was a volcanic eruption in Nicaragua. In 1910, after the passage of a comet, massive epidemics began on Earth, including the famous "Spanish Flu", which claimed millions of lives. There was an epidemic of bubonic plague in India. In 1986, there was an accident at the Chernobyl nuclear power plant, the echoes of which we still feel.
Of course, all this is nothing more than a coincidence. Every year, even without the appearance of a comet, natural disasters and man-made disasters occur.
Comet's next appearance
In 1986, when Halley's comet last appeared, it disappointed astronomers. Conditions forher observations from Earth in the past 2,000 years have been the worst. A comet is best observed at perihelion, when its tail is longest and its nucleus is brightest. But this year, the comet arrived in February and its perihelion was on the opposite side of the Sun from the Earth, so it was closed for observation.
The next time Halley's Comet will fly by is July 2061. It must be clearly visible. You can watch it for 4 months. It will be especially well visible at dawn and before sunset.
